A list of libraries for AsyncIO is available on PyPI with Framework::AsyncIO classifier.

• uvloop: Ultra fast implementation of asyncio event loop on top of libuv. Read more about uvloop here.
• async-tokio: Asyncio event loop implementation, written in Rust language

• aiofiles: File support for asyncio
• aiocache: Caching for asyncio with multiple backends (framework agnostic)
• aiorwlock: Read write lock for asyncio
• aioutils: Python3 Asyncio Utils, Group (like gevent.pool.Group), Pool (like gevent.pool.Pool), Bag and OrderedBag
• tasklocals: Task-local variables
• janus: Thread-safe asyncio-aware queue
• asyncio_extras: asynchronous generator/context manager support, thread pool integration, async file operations and more
• paco: Small utility library for coroutine-driven asynchronous programming
• aioconsole: Asynchronous console and interfaces for asyncio
• aiostream: Generator-based operators for asynchronous iteration

• asynctest: Enhance the standard unittest package for testing asyncio libraries
• pytest-asyncio: Pytest support for asyncio

• AMQP:
  • aioamqp: AMQP implementation using asyncio (Used by RabbitMQ)
  • QBroker: easy-to-use library based on aioamqp, for pub/sub and RPC
• AMI: panoramisk, a library to play with Asterisk's protocols: AMI and FastAGI
• Cassandra: aiocassandra, Simple threaded cassandra wrapper for asyncio
• CouchDB: aiocouchdb, CouchDB client
• DNS: aiodns: Async DNS resolver
• ElasticSearch:
  • aioes: ElasticSearch client library
  • elasticsearch-py-async: aiohttp transport for official elasticsearch-py driver
  • aioelasticsearch: aiohttp transport for elasticsearch-py with additional asynchronous interface
• Etcd: aioetcd: Coroutine-based etcd client
• Google Hangouts: hangups: Client for Google Hangouts
• HTTP: aiohttp.requests: http client with Requests-like API.
• IRC:
  • irc3, plugable irc client library based on python's asyncio
  • bottom, asyncio-based rfc2812-compliant IRC Client
• Kafka: aiokafka: Full featured Kafka client for Kafka 9.0.0+
• memcached: aiomemcache, minimal memcached client
• MongoDB:
  • Motor, official async MongoDB driver
  • asyncio-mongo, MongoDB driver (ported from Twisted)
• MPD: aiompd, Music Player Daemon client for AsyncIO
• MySQL: aiomysql, MySQL driver
• ODBC: aioodbc, ODBC client on top of pyodbc, works only with python 3.5+
• PostgreSQL:
  • aiopg, PostgreSQL client library built on top of psycopg2
  • aiopg8000, A Pure-Python PostgreSQL driver for AsyncIO
  • asyncpg, A fast PostgreSQL Database Client Library for Python/asyncio
• Prometheus: prometheus_async adds support for asynchronous frameworks to the official Python client for the Prometheus metrics and monitoring system.
• PySerial: asyncserial: asyncio support for pySerial
• Redis:
  • asyncio-redis, Redis client with pubsub support
  • aioredis, Yet another Redis client
• Riak: aioriak: Python asyncio client for Riak
• Slack aioslacker: slacker wrapper for asyncio
• SIP: aiosip: SIP support for AsyncIO
• Socks: aiosocks: SOCKS proxy client for asyncio and aiohttp
• SSH: AsyncSSH: SSH client and server implementation
• WebSockets: aiohttp.ws_connect: WebSockets client
• XMPP (Jabber):
  • slixmpp, SleekXMPP (XMPP Library) fork using asyncio, for poezio,
  • aioxmpp, from scratch XMPP library for asyncio (alpha)
• Zipkin: aiozipkin: Distributed tracing instrumentation for asyncio with zipkin

• FastAGI: panoramisk, a library to play with Asterisk's protocols: AMI and FastAGI
• IRC: irc3d, irc server library based on irc3
• HTTP: aiohttp: http client and server infrastructure for asyncio
• SSH: AsyncSSH: SSH client and server implementation
• SMTP/LMTP: aiosmtpd: Server implementations and testing frameworks for Simple Mail Transport Protocol and Local Mail Transport Protocol.

Looking for WSGI? Read this thread: WSGI implementation compatible with asyncio?.

• aiohttp.web: a Flask-like API to build quickly HTTP applications, made by the creators of aiohttp
• aiopyramid: Tools for running pyramid using asyncio
• aiotraversal: Web framework for big complicated applications based on aiohttp
• aiowsgi: minimalist wsgi server using asyncio
• Growler: A web framework built on top of aiohttp
• interest: event-driven web framework on top of aiohttp/asyncio
• muffin: A web framework based on Asyncio stack (early alpha)
• nacho: web framework
• Pulsar: Event driven concurrent framework for python. With pulsar you can write asynchronous servers performing one or several activities in different threads and/or processes.
• rainfall: another web framework
• sanic: A Flask-like Python 3.5+ web server that's written to go fast.
• Vase: web framework

• aiohttp.web: a Flask-like API to build quickly HTTP applications, made by the creators of aiohttp.
• AutobahnPython: WebSocket and WAMP framework
• websockets: Websockets library
• WebSocket-for-Python: another websocket library

• aiopg.sa: support for SQLAlchemy functional SQL layer, based on aiopg
• aiomysql.sa: support for SQLAlchemy functional SQL layer, based on aiomysql
• peewee: peewee-async, library providing asynchronous interface powered by asyncio for peewee ORM.
• GINO: lightweight ORM based on asyncpg and SQLAlchemy core

• API-Hour: Transform easily your AsyncIO server source code (HTTP, SSH, ...) to be multiprocess: it will help to improve the efficency on multi-CPU servers.
• Gunicorn: Gunicorn has gaiohttp worker built on top of aiohttp library

• ktcal2: SSH brute forcer tool and library, using AsyncIO of Python 3.4

• eventlet: aioeventlet, asyncio API implemented on top of eventlet

Some people have already written adapters for integrating asyncio with other async I/O frameworks.

• eventlet: greenio, Greenlets support for asyncio (PEP 3156)
• gevent: tulipcore, run gevent code on top of asyncio, alternative gevent core loop
• GLib: gbulb, event loop based on GLib
• libuv: aiouv, an event loop implementation for asyncio based on pyuv
• Qt: Quamash, implementation of the PEP 3156 Event-Loop with Qt.
• Tornado has experimental asyncio support built right into it.
• ZeroMQ:
  • aiozmq, ZeroMQ integration with asyncio
  • Zantedeschia, experimental alternative integration between asyncio and ZeroMQ sockets.

• aioauth-client: OAuth1/2 support (authorization, resource's loading)
• aiocron: Crontabs for asyncio
• aiomas: A library for multi-agent systems and RPC based on asyncio
• aiotest: test suite to validate an implementation of the asyncio API
• aioprocessing: A Python 3.3+ library that integrates the multiprocessing module with asyncio
• blender-asyncio: Asyncio Bridge for Blender Python API
• ipython-yf: An ipython extension to make it asyncio compatible
• aiogearman: asyncio gearman support. Gearman provides a generic application framework to farm out work to other machines or processes that are better suited to do the work.
• aiogear: Yet another gearman protocol implemented in asyncio.
• Serial port using the serial module, see using serial port in python3 asyncio at Stackoverflow, serial.Serial can be registered with loop.add_reader().
• async_lru: port of functools.lru_cache to asyncio
• GoogleScraper: A Python module to scrape several search engines (like Google, Yandex, Bing, Duckduckgo, Baidu and others) by using proxies (socks4/5, http proxy) and with many different IP's.
• aiotasks: A Celery like task manager that distributes Asyncio coroutines.

asyncio does not support asynchronous operations on the filesystem. Even if files are opened with O_NONBLOCK, read and write will block.

Read asynchronous disk I/O (October 2012 by arvid).

The Linux kernel provides asynchronous operations on the filesystem (aio), but it requires a library and it doesn't scale with many concurrent operations. See aio.

The GNU C library (glibc) implements the POSIX aio interface, but it is implemented with threads. See aio(7) manual page.

Recent discussion on the Linux Kernel: Non-blocking buffered file read operations (September 2014).

For now, the workaround is to use aiofiles that uses threads to handle files.